1. Field of the Invention
The present invention relates to a liquid filtering instrument for filtering liquid, and particularly to a liquid filtering instrument suitably used to prepare blood plasma or blood serum samples from blood of humans or other animals. Furthermore, the present invention relates to a dry type analysis device for filtering body liquid such as blood, urine or the like under reduced pressure and analyzing the body liquid thus filtered.
2. Description of the Related Art
Recently, a compact type filter unit in which a filter is mounted in advance has been frequently used when liquid such as organic solvent or the like is filtered in a chemical experiment.
“Chromatodisc 13N” sold by GL Science Inc. is known as a filter unit which is generally used for chemical experiments. This filter unit uses porous membrane of polytetrafluoroethylene (PTFE) as a filter, and it is designed by unifying plural housing members of polypropylene (PP) into one body through fusion.
When body liquid such as urine, blood or the like is filtered, a compact cartridge type filter unit is used (for example, see Japanese Published Unexamined Patent Application No. H9-196911). The cartridge type filter unit is generally formed as follows. That is, a filter is pinched by plural resin housing members and fused by ultrasonic waves or the like so that the filter and the resin housing members are unified into one body.
Furthermore, there has been developed a filter unit filled with a filter which can separate blood cells to take out blood plasma from whole blood (for example, see Japanese Published Unexamined Patent Application No. H10-227788 (FIG. 1)). Products on the market are known as this filter unit, and for example, “FUJI DRI-CHEM PLASMA FILTER PF” sold from Fujifilm Medical Co., Ltd. is known. This filter unit employs polysulfone (PSF) porous membrane as a filter, and transparent polystyrene (PS) housing members are unified into one body by ultrasonic fusion.
A method of diagnosing disease of humans or other animals while body liquid such as blood, urine or the like is used as a specimen has been carried out for a long time as a simply and easy method of performing diagnosis without damaging human bodies. As one method of analyzing blood, urine or the like has been developed a so-called dry chemistry analysis method which does not use solution, that is, in which a reagent group needed to detect a specific component is contained under a dry state (Yuzo Iwata, “11. Other analytical method (1) dry chemistry,” Laboratory Chemical Practice Manual, issued by Igaku-Shoin Ltd. 1993, Issue Number of “Kensa To Gijyutsu,” Vol. 21, No. 5, p. 328-333).